
DEPARTMENT OE THE INTERIOR 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS, SMITH, Director 


WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1914 


Wonograph 


Bulletin 580—J 


THE PHOSPHATE DEPOSITS 
OF SOUTH CAROLINA 


BY 


G. SHERBURNE ROGERS 


CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913„ PART I—J 

























































































X 





DEPARTMENT OF THE INTERIOR 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 


Bulletin 580—J 


THE PHOSPHATE DEPOSITS 
OF SOUTH CAROLINA 



BY 


G:SHERBURNE ROGERS 


CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I—J 



WASHINGTON 

GOVERNMENT PRINTING OFFICE 


1914 







CONTENTS. 


-UsT^e 


Introduction. 

Geography and topography. 

Geology. 

Stratigraphy. 

Sequence of the strata. 

Tertiary system. 

Eocene series. 

Cooper marl. 

Oligocene series. 

Miocene series. 

Edisto marl. 

Duplin marl. 

Pliocene series. 

Waccamaw marl. 

Quaternary system. 

Pleistocene series. 

Structure... 

Geologic history. 

Phosphate rock. 

Physical character. 

Chemical composition. 

Persistence of bed. 

Distribution. 

Quantity. 

Origin. 

Earlier theories. 

Residual-soil theory. 

Phosphate industry.. 

Prospecting and mining methods 

Land mining. 

River mining. 

Preparation of the rock. 

Economic factors. 

Workability. 

Cost of production. 

Grade of product. 

History of field. 

Discovery. 

Development. 

Present condition. 

Future of field. 


Page. 

183 

184 

185 
185 

185 

186 
186 
186 

187 

188 
188 

• 189 
189 
189 
189 
189 
191 

191 

192 
192 
195 
198 
200 
202 
203 
203 
205 
209 
209 
209 
211 
211 
213 

213 

214 

215 
215 

215 

216 
219 
219 


ILLUSTRATIONS. 


Page. 

Plate II. Map showing approximate original distribution of South Carolina 

phosphate deposits. 184 

Figure 55. Map and sections showing irregularity of phosphate stratum near 


north branch of Stono River, S. C. 198 

56. Sections showing depth of phosphate bed below surface along line 

E-E' on figure 55. 199 


D. Gf, 0. 

OCT W 5914 

». * 


II 

















































N THE PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


By G. Sherburne Rogers. 


INTRODUCTION. 

The deposits of phosphate rock in the vicinity of Charleston, S. C., 
were among the first discovered in the United States, and until 
about 20 years ago the field was one of the largest producers m the 
world. The workable deposits are confined to the region lying in 
general between Charleston and Beaufort and extending about 25 
miles back from the coast. The phosphate rock occurs in a thin bed 
which underlies irregular areas within the region defined. This bed 
is commonly less than 18 feet below the surface, and is thus compara¬ 
tively easy to mine, but, owing to the rather low grade of the rock 
and the exploitation of richer and more easily accessible deposits in 
Florida and Tennessee, production in the South Carolina field has 
now almost ceased. A number of papers describing this field have 
been published, most of them 20 years or more ago, but in view of the 
present more extended geologic information concerning this region it 
has been thought advisable to prepare this account, which is based 
on a brief field study by the writer. 

The examination of the field was made in January, 1914. The 
writer is indebted to Mr. Earle Sloan, formerly State geologist of 
South Carolina, for many courtesies and for some unpublished infor¬ 
mation concerning the geology. Mr. John Hertz, who has long been 
engaged in phosphate mining, kindly contributed several maps and 
furnished valuable data, and Messrs. William Gaillard, Bachman 
Smith, and William Alston assisted in many ways. In addition to 
information privately communicated, several of the earlier reports 
on the field have been freely drawn upon for pertinent facts. 

The earliest report on the phosphate deposits was published in 
1868 by N. A. Pratt,^ and this was followed in 1870 by a more extended 
account by F. S. Holmes.^ Both of these papers are written in 
narrative and more or less popular form. In 1870 N. S. Shaler^ 
contributed a short scientific description. In 1880 C. U. Shepard, jr.,^ 

1 Ashley River phosphates, Philadelphia, 1868. 

2 Phosphate rocks of South Carolina, Charleston, 1870. 

3 On the phosphate beds of South Carolina: Boston Soc. Nat. Hist. Proc., vol. 13, pp. 222-235,1870: U. S. 
Coast Survey Kept., pp. 182-189,1870. 

< South Carolina phosphates. Charleston, 1880. 






184 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

published the most complete and valuable of the earlier reports on 
the field. In 1888 K. A. F. Penrose, jr.,^ wrote for the United States 
Geological Survey a bulletin on phosphate which contains a good 
though brief account of the South Carolina deposits. In 1891 a 
book on American phosphate by Francis Wyatt ^ appeared, in 1892 
a book on phosphate by C. C. H. Millar,^ and in 1895 a study of the 
phosphate industry by David Levat,^ all three of which deal with 
the South Carolma field at greater or less length, but discuss chiefly 
the mining and product costs. Charles L. Reese ^ published a shoit 
paper on the region of the deposits‘based on a series of chemical 
experiments. An extended account of the field and narrative of its 
discovery and history, prepared primarily for newspaper publication, 
was written by P. E. Chazal« in 1904. In 1908 Earle Sloan,^ State 
geologist, published a '‘Catalogue of the mineral localities of South 
Carolina,” which contains geologic sections measured at a number of 
places and a short account of the phosphate. In 1913 William H. 
Waggaman,^ of the United States Department of Agriculture, 
wrote a brief report on the field, dealing chiefly with the state of the 
industry and methods of production. In addition to these general 
papers, an elaborate description by Joseph Leidy ^ of the vertebrate 
fossils found in the phosphate beds appeared in 1881, and a brief 
account of some of the invertebrate forms by W. H. Dali in 1894. 

GEOGRAPHY AND TOPOGRAPHY. 

The phosphate deposits are confined to a seaboard zone, most of it 
less than 30 miles in width, which extends from Beaufort on the south 
to a point about 20 miles beyond Charleston on the north. (See PI. 
II.) The most important deposits, however, are situated between 
the mouth of Broad River and a point near the source of Wando 
River and lie within a rough arc terminating at these points and 
extending farthest back along Edisto River. Within this segment the 
phosphate underlies irregular areas whose boundaries have not been 
exactly defined but which are approximately dehmited on the accom¬ 
panying map. 

The principal cities within this area are Charleston and Beaufort, 
the former being the center of the phosphate and fertilizer industry. 

1 Nature and origin of deposits of phosphate of lime: U. S. Geol. Survey Bull. 46, pp. 60-70,1888. 

2 Phosphates of America, pp. 44-61, New York, 1891. 

3 Florida, South Carolina, and Canadian phosphates, pp. 123-178, London, 1892. 

* Industrie des phosphates et superphosphates, pp. 83-90, Paris, 1895. 

3 On the influence of swamp waters in the formation of the phosphate nodules of South Carolina: Am. 
Jour. Sci., 3d ser., vol. 43, pp. 402-406,1892. 

6 Sketch of the South Carolina phosphate industry. Charleston, 1904. 

7 South Carolina Geol. Survey, 4th ser.. Bull. 2,1908. 

3 Report on the phosphate fields of South Carolina: XJ. S. Dept. Agr. Bull. 18,1913. 

9 Description of vertebrate remains, chiefly from the phosphate beds of South Carolina: Jour. Acad. Nat. 
Sci. Philadelphia, vol. 8, 2d ser., pp. 209-262, 1874-1881. 

10 Notes on the “land phosphate” of the Ashley River district, S. C.: Am. Jour. Sci., 3d ser., vol. 48, 

pp.300-301, 1894. 




U. S. GEOLOGICAL SURVEY 


BULLETIN 580 PLATE II 



Moncks Comer 


^Wando 


AValterl) 


ATLANTIC 


Laoid rock 

(Density of pcctiern indicates 
value of deposit) 


River rock 

(Deposits mostly exhausted) 





jSIOZZXD 


^ 1 


(P/~^ A 




MAP SHOWING APPROXIMATE ORIGINAL DISTRIBUTION OF SOUTH CAROLINA PHOSPHATE DEPOSITS. 



































PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 185 

In previous years a large amount of phosphate rock was shipped fro m 
these points or from docks located farther up the rivers in their 
vicinity. The Atlantic Coast Line, the Southern Railway, and the 
Charleston & Western Carohna Railway cross the area, and most of 
the phosphate properties are located either on the main lines or on 
short spurs of these roads. 

The coast in this vicinity is low and extremely irregular in outline 
and is bordered by numerous islands. It is intersected in the most 
intricate manner by numberless tidewater channels which range in 
width from a few feet up to several miles, one of the widest being 
Broad River at Port Royal. Many of these channels run almost 
parallel to the coast and thus form islands, and in some localities they 
have intersected the coast to such an extent that two or three tiers 
of islands have been formed.^ In addition to these arms of the sea, 
many of which extend considerable distances back from the coast 
proper, some of the streams and rivers that traverse this region have 
developed a system of tidewater distributaries. Edisto, Ashepoo, 
and Broad rivers are conspicuous examples of streams of this type, 
which, in conjunction with the waterways mentioned above, have 
intricately dissected the general coastal region. (See PL II.) Most 
of the rivers are broad, sluggish streams and are navigable for con¬ 
siderable distances above their mouths, affording ready means of trans¬ 
portation for the phosphate. 

The topography within the whole phosphate-bearing area is very 
uniform, bemg everywhere of the Coastal Plain type. The land is 
almost fiat and is for the most part less than 15 feet above tide; ele¬ 
vations of more than 25 feet are uncommon. Most of it is wooded 
and is swampy in character, being practically covered with water for 
at least part of the year. In the course of the phosphate mining dur¬ 
ing the last 45 years many large areas have been worked over with 
steam shovel or by hand, and these tracts, in which the surface is 
broken, swampy, and covered with dense thickets, are now practi¬ 
cally impassable. 

GEOLOGY. 

STRATIGRAPHY. 

SEQUENCE OF THE STRATA. 

Owing to the wealth of fossil remains which some of the strata in 
this region contain they have attracted the attention of many observ¬ 
ers. Rufiin,^ Tuomey,^ Pratt,^ Holmes,^ and Shepard,® all give more 

1 A good account of the configuration of the coast, the submarine topography, etc., is given by N. S, Shaler 
in U. S. Coast Survey Kept., 1870, pp. 182-185. 

2 Ruffin, Edmund, Agricultural survey of South Carolina, Columbia, 1843. 

3 Tuomey, Michael, Report on the geology of South Carolina, Columbia, 1848. 

< Pratt, N. A., Ashley River phosphates, Philadelphia, 1868. 

5 Holmes, F. S., Phosphate rocks of South Carolina, Charleston, 1870. 

6 Shepard, C. U., jr.. South Carolina phosphates. Charleston, 1880. 



186 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

or less extended descriptions of the geology. Their work has been 
largely superseded, however, by the detailed investigations of Sloan ^ 
and the broad areal studies of Vaughan.^ In conformity with the 
results of this recent work the following classification has been adopted 
by the United States Geological Survey for the formations treated in 
this report: 

Geologic formations related to the phosphate deposits of the Charleston region, S. C. 


Sys¬ 

tem. 

Series. 

Formation. 

Approxi¬ 

mate. 

thickness. 

Character. 

Qua¬ 

ter¬ 

nary. 

Pleistocene. 

Undifferentiated. 

Feet. 

Variable. 

Sand, gravel, loam, etc. 


Pliocene. 

u iicoiiioriiiiiy 

Waccamaw marl. 

11 

Compact granular marl; upper part 
brownish yellow, lower part gray. 


Miocene. 

u ncoiiioriiiicy 

Duplin marl. 

35 

YeUow marl; upper part very hard, char¬ 
acterized by Pecten eboreus; middle 
compact to porous, containing Cham a 
striata and A rca incile; lower friable and 
porous, containing Amusium mortoni. 

Ter¬ 

tiary. 

u ncoiiioriiiiiy 

Edisto marl. 

0-4 

Marl, commonly more or less phospha- 
tized; compact in texture,but containing 
many large cavities: color light where 
unaltered, darker where phosphatized; 
source of the commercial phosphate. 


Oligocene. 

Apparently unrepresented 
in this area. 




Eocene. 

Cooper marl. 

100-F 

Marl, light grayish green to dark greenish 
drab. 


TERTIARY SYSTEM. 

EOCENE SERIES. 

Cooper marl .—The Cooper marl is the lowest formation here con¬ 
sidered, though earlier Eocene is well developed within the general 
phosphate-bearing area. The Cooper conformably overlies the 
Barnwell sand (equivalent in part to the Mount Hope marl of Sloan), 
which is the highest formation of the Claiborne group in this region. 
The Cooper is therefore in whole or in part referable to the Jackson 
group, the highest division of the Eocene, but diagnostic fossils are 
rare and the exact age of the upper part of the formation has not yet 
been determined. The Cooper is, however, almost entirely late 
Eocene, but its higher strata may have been deposited in early 
Oligocene time. 

The formation consists of over a hundred feet of grayish-green 
marl; the lower part (the Cooper marl of Sloan) is greenish drab in 
color and somewhat plastic when wet, but lighter colored and fairly 


-1 Sloan, Earle, South Carolina Geol. Survey, 4th ser.. Bull. 2,1908. 

2 For discussion by Vaughan see Willis, Bailey, Index to the stratigraphy of North America: U. S. Geol. 
Survey Prof. Paper 71, pp. 806-813, 1912. 
























PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


187 


hard when dry. It commonly contains about 75 per cent lime car¬ 
bonate and about 2 per cent lime phosphate. The upper part of the 
formation (the Ashley marl of Sloan) is dull ohve green and semi- 
plastic when wet and drab when dry. The content of lime carbonate 
is somewhat lower than that of the lower division of the formation, 
but the phosphate is considerably higher, commonly exceeding 5 per 
cent. (See analyses, p. 208.) 

Shepard ^ gives an interesting well section made at Sineaths station, 
which presumably includes the greater part of the Cooper and prob¬ 
ably also part of the underlying Claiborne group. The section is, 
unfortunately, not complete, but gives only the depth of certain 
strata which Shepard analyzed for phosphate. (See analyses, p 208.) 
It shows, however, that thin layers of large nodules containing 50 per 
cent or more of phosphate occur at depths of 26, 70, and 110 feet 
below the surface, and that the inclosing marl contains phosphate in 
amounts varying from a trace to 3 per cent. 

The exact thickness of the Cooper marl has not been determined. 
The Cooper is being quarried at Woodstock, about 15 miles north of 
Charleston. At the time of the writer’s visit only about 65 feet was 
exposed, but it is reported that the base of the marl had been reached 
by drilling to a depth of 140 feet. It is possible, however, that this 
may include part of an underlying formation. An excellent section 
of the Cooper is exposed at the Woodstock pit, from which about 
5,000 tons a year is quarried for use as a base or ‘‘filler” for the com¬ 
mercial fertilizer. The marl is sufficiently coherent to form the 
vertical walls of the deep pit, yet soft enough to be worked with pick 
and shovel. It is blasted out, broken up, and transported by bucket 
hoist to the shed, where it is burned and ground. The marl is com¬ 
pact and impervious to water, so that the pit is fairly dry. Inverte¬ 
brate fossils are rather scarce, but fragments of bone are not 
uncommon. 

OLIGOCENE SERIES. 

« 

In the phosphate area the Ohgocene is apparently not represented, 
and the Edisto marl (Miocene), the source of the phosphate with which 
this paper is primarily concerned, rests directly on the Cooper marl 
(Eocene). 

It may be pointed out, however, that the absence of Ohgocene 
strata does not necessarily imply that they were never deposited. 
The Cooper marl may overlap shghtlyintoOhgocene time (seep. 186), 
and this suggests that there may have been no marked break at the 

1 Shepard, C. U., jr., Rural Carolinian, August, 1873, See also Chazal, P. E., loc. cit., and Waggaman, 
W. 11., loc. cit. 



188 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

end of the Ecoene and that deposition may have continued for some 
time. If it did, then all the strata down to the present top of the 
Cooper must have been eroded during the subsequent elevation of the 
land. 

MIOCENE SERIES. 

Edisto marl .—In this region the Edisto marl, the source of the phos¬ 
phate rock, rests directly and imconformably on the Cooper marl, the 
hiatus representing all or nearly all of the Oligocene as well as the 
lowest Miocene. Similarly, the Edisto is commonly overlain directly 
by the Quaternary, although two higher Tertiary formations are well 
'recognized in this general area. Although its identifiable fossils are 
few the Edisto is believed by Vaughan ^ to be middle Miocene—about 
equivalent to the St. Marys formation of Maryland and Virginia. 
The opinions of the older workers as to the age of the Edisto differed 
widely. Tuomey^ referred it to the Eocene; Holmes, Shepard, and 
Chazal considered it an altered conglomerate of Eocene marl depos¬ 
ited in post-Pliocene time; and Pratt believed it to be Recent. Hall ^ 
in 1894 first definitely established its age as Miocene. 

According to Sloan ^ the Edisto in its unaltered form is a yellow- 
white marl, commonly 4 to 5 feet thick. Although compact in texture ’ 
it is penetrated in many places by tortuous cavities, some organic in 
origin and others apparently due to solution. It has been found in 
its unaltered form at only a few localities, being commonly phospha- 
tized. The two forms may be observed in close proximity in the bed 
of Stono River near the mouth of Wappoo Cut. In the phosphatized 
form the bed is generally thinner, averaging about 1 foot and at 
few places exceeding 2^ feet. The phosphatized mass is fairly hard 
and is irregular in outline and honeycombed with many cavities. 
These may reach 4 inches or more in diameter and in some localities 
are so large that the rock is mostly broken up into irregidar nodules. 
The filling of the cavities (or of the matrix when the bed is separated 
into fragments) is a black sandy clay, generally calcareous and phos- 
phatic and in many places carrying abundant vertebrate remains. 
These are chiefly cetacean bones and sharks’ teeth and vertebrae, but 
the coprolites and bones of late Miocene, Pliocene, and Quaternary 
land animals are also plentiful. A few distinctively Eocene shells, 
generally waterworn, are also found in this material. The phosphate 
rock itself, however, contains numerous casts and molds of the same 
shells that characterize the unaltered Edisto marl.® 

In addition to this regularly stratified form the phosphate rock is • 
also found in irregrdar deposits in the beds of many of the rivers. 


1 U. S. Geol. Survey Prof. Paper 71, p. 807, 1912. 

2 Tuomey, Michael, op. cit., pp. 164-165. 

3 Am. Jour. Sci., 3d ser., vol. 48, pp. 300-301, 1898. 


< Sloan, Earle, op. cit.,p. 470. 
6 Idem, p. 299. 




PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


189 


This river rock generally consists of rounded pebbles, and is commonly 
darker in color and higher in specific gravity than the ordinary land 
rock. It is probable that these deposits were in part laid down during 
Edisto time, but that they were subsequently worked over by river 
action and were increased in thickness by the erosion and concentra¬ 
tion of the land deposits. 

Duplin marl .—The Duplin marl, an extension of the marl of the 
same name in North Carolina, includes the ^Teedee’’ and Goose 
Creek’' marls of Sloan. It is upper Miocene in age. The lower part 
of the Duplin marl (the '‘Goose Creek marl” of Sloan) is a soft yellow 
porous marl containing over 80 per cent of carbonate of lime. Ac¬ 
cording to Sloan it overlies the unphosphatized Edisto ^ at Givhams 
Ferry, and its outcrop near Goodrich station sharply delimits on the 
south that of the phosphatized Edisto.^ At the latter place it con¬ 
tains near the contact nodules of phosphate rock that prove it to be 
younger, but although it presumably overlies the phosphate to the 
south it was not actually observed in this position. Except for these 
two localities the Edisto and Duplin marls have not been observed 
in the same section and in the main appear to occupy different areas. 

The soft yellow porous marl is overlain in places by 25 feet of harder 
and more compact yeUow marl, to which Sloan has applied the name 
“Peedee marl.” There appears to he no significant faunal or litho¬ 
logic differences between the two, however, and they are therefore 
grouped by Vaughan under the name Duplin marl. The upper mem¬ 
ber (“Peedee marl” of Sloan) has not been observed in contact with 
the Edisto. 

PLIOCENE SERIES. 

Waccamaw marl .—The Pliocene series in South Carolina is repre¬ 
sented by the Waccamaw marl, which occurs only in Horry County 
near the North Carolina-South Carolina State line. It is not found 
in contact with the Edisto, the phosphate-bearing formation, and is 
here included for the sake of completeness. It is described by Sloan 
as a compact granular marl about 11 feet thick, brownish yellow at 
the top and gray beneath. 

QUATERNARY SYSTEM. 

PLEISTOCENE SERIES. 

The Pleistocene deposits have been differentiated by Sloan into a 
number of subdivisions, but as their broader relations are not well 
established they are here treated as a unit. Because of the conditions 
described above, the Pleistocene generally rests directly on the Edisto 
within the phosphate-bearing area and constitutes the overburden 

1 Sloan, Earle, op. cit., p. 283. * Idem, p. 291. 

52639°—14-2 





190 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

which must be removed in mining. It consists of clay, marl, sand, 
and gravel, 20 feet or more in thickness. This material has been 
divided by Sloan ^ as follows: 

5. Sea Island loams. Fine, glauconitic sand and silt, probably derived from the 
reworking of the Bohicket marl sands. 

4. Wando clays and sands. White sand overlain by drab to red clay. 

3. Accabee gravels, generally absent. Pebbles of quartz and phosphate rock 
derived from the reworking of the Edisto marl. 

2. Bohicket marl sands. Fine-grained, greenish to bluish-green glauconitic sand. 

1. Wadmalaw marl. Greenish-gray sandy marl inclosing large numbers of Pleisto¬ 
cene shells. 

This classification appears to hold within the phosphate-bearing 
area, although the complete section is probably not exposed at any 
one place. In addition Sloan differentiates what he calls the Ten- 
mile sands, which were deposited in early Pleistocene time in the form 
of a barrier ridge, on the seaward side of which the above-mentioned 
deposits were laid down. 

Sloan’s Wadmalaw marl is in general only 2 to 3 feet thick and is 
fairly persistent. It is overlapped by his Bohicket marl sands, which 
extend several miles beyond it to the north and are almost invariably 
present in the material overlying the phosphate and in places are 10 
feet or more thick. These deposits are somewhat glauconitic and at 
the Bolton mines contain 2.19 per cent of potash. The Acca¬ 
bee gravels of Sloan form an interesting example of the reworking 
of an older bed. According to Sloan the material was derived from 
the partial disruption of the shoreward edge of the Edisto marl by 
wave action, especially in the Wando and Cooper basins. The area 
of the gravel is very small; where present it is generally less than a 
foot thick, though in places it attains a thickness of 4 feet. It has 
afforded a limited supply of phosphate and is known to the miners as 
the ^ ‘Flying Rock bed.” The Wando clays and sands of Sloan overlie 
the gravel in places, the sands being widely distributed. Sloan’s Sea 
Island loams are best developed along the zone of the sands to which 
he apphed the name “Bohicket” and are probably derived from them. 

The character of the Pleistocene deposits that overlie the Edisto is 
illustrated by the following sections: 

Section at Bolton mine, Charleston County? 

Feet. 


Vegetable muck. 4 

Clay, green, sandy, glauconitic (Bohicket of Sloan). 5 

Sand (Bohicket of Sloan). 3 

Marl, highly fossiliferous (Wadmalaw of Sloan). 2 

Phosphate rock (Edisto). 2 


16 


1 Sloan, Earle, op. cit., pp. 480-484. 


2 Idem, p. 298. 









191 


PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


Section near Lambs, Charleston County. 
[Measured by G. S. Rogers.] 

Vegetable muck. 

Sand, white, brownish at top (Wando (?) of Sloan). 

Sand, yellow. 

Sand, bluish-green, clayey (Bohicket of Sloan). 

Phosphate rock (Edisto). 


Feet. 

1 

6 

1 

3 

1 


12 

Section at Simmons Bluff, Youngs Island, Colleton Cjunty.^ 

Ft. in. 


Soil, sandy. 2 0 

Wando (?) of Sloan: 

Loam, red, becoming clayey toward base. 6 0 

Clay, white, sandy, plastic. 1 6 

Sand, white, fine. X 5 

Bohicket of Sloan: 

Clay, green, glauconitic. 3 o 

Wadmalaw of Sloan: 

Xoose shells. 34. 


STRUCTURE. 


17+ 


The strata in the South Carolina phosphate area have undergone 
little or no tilting and for the most part lie almost flat. Such varia¬ 
tions from the horizontal as they exhibit are due chiefly to the char¬ 
acter of the old surface on which they were deposited. All the for¬ 
mations have a slight but gentle dip toward the sea owing to the 
shelving character of the old surface; and as this surface was in places 
irregular most of the formations vary considerably in thickness and 
in some localities are absent. 


GEOLOGIC HISTORY. 

During late Eocene time the region here considered was covered by 
the sea and the submergence may have extended into early Ohgocene 
time. During this period the Cooper marl was laid down to a thick¬ 
ness of over 125 feet. At some time during the Ohgocene the land 
was elevated and remained above the sea for a long time, during which 
a portion of the upper part of the Cooper was removed by erosion. 
According to Sloan the shore line during this period was roughly 
coincident with the present position of Wando and Stono rivers. 
(See PI. II.) At the opening of the middle Miocene the land was again 
partly submerged, and the Edisto was deposited on the irregular upper 
surface of the Cooper. The hills of the old surface were perhaps in 
part submerged and in part formed low islands, on which the Edisto 
was never laid down. This formation thus appears to be entirely 


1 Sloan, Earle, op. cit., p. 300. 















192 COISTTEIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

lacking in the area between Ashepoo and Combahee rivers and in 
several smaller districts. The old surface was somewhat shelving, 
as is indicated by the present slight dip (3.3 feet to the mile) of the 
Edisto toward the sea. Farther seaward this inclination of course 
increased, and the Edisto therefore dips sharply below the present 
surface along the southern boundary of the phosphate area, as 
indicated roughly on the map (PI. II). Thus, according to Shepard,^ 
the Edisto at Charleston is about 60 feet below the surface. After 
its deposition the Edisto marl underwent certain chemical changes, 
which increased its phosphate content. (See p. 206.) 

At the end of Edisto time a shght elevation of the land took place 
and the Duphn marl was laid down within the area which stiU 
remained below water. A further elevation of land occurred at the 
end of Miocene time, and no more marine sediment was laid down in 
the immediate phosphate area until the Pleistocene. 

Accordmg to Sloan the earliest Pleistocene formation is his Ten- 
mile sands, which were deposited in the form of a barrier ridge along 
a zone near the north border of the phosphate area. During the 
gradual subsidence which followed, the deposits called by Sloan the 
Wadmalaw, Bohicket, and Accabee were deposited against the sea¬ 
ward side of this ridge as a progressively overlapping series. The 
relations of the deposits to which he gave the names Wando and Sea 
Island are less clear, but they appear to have been laid dovm during 
the gradual reelevation which doubtless brought the land to its present 
altitude. 

PHOSPHATE ROCK. 

PHYSICAL CHARACTER. 

The phosphate was described by Pratt in 1868 and by Shepard in 
1880 as essentially nodular in character, and this description has ap¬ 
parently been followed by most subsequent writers. From a com¬ 
mercial standpoint this description is sufficient, for the land phosphate 
as mined generally occurs in small and more or less rounded fragments, 
and the river rock, which was extensively mined in the early days of 
the industry when the term was first used, is decidedly nodular in 
appearance. Geologically, however, the term is unfortunate, for it 
implies much in the way of genesis and history that is probably 
incorrect. 

The two varieties of the phosphate, land rock and river rock, differ 
somewhat in character. The land rock occurs in a more or less irreg- 
ular bed wMcb represents the undisturbed phosphatized Edisto marl; 
tbe river rock probably consists in part of the original phosphatized’ 
Edisto and in part of fragments derived from the land deposits and 


1 Shepard, C. South OaroUna phosphate, p. 20, Charleston, 1880. 





PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 19S 

concentrated on the river bottom, the whole deposit having been 
more or less worked over by river action. To these may be added a 
third kind, the Accabee gravels of Sloan, which are a later deposit 
formed by the reworking of the original bed. 

The land rock occurs in a bed which has a maximum thickness of 
30 inches, but averages probably between 8 and 16 inches, and is in 
many places absent. It generally consists of an irregular or even 
jagged mass of rock honeycombed by many tortuous cavities, but its 
upper surface is in many places smoother and more compact than 
the lower. In places the cavities are as much as 4 inches in diameter 
and thus afford lines of weakness which cause the bed to break up 
easily when disturbed in mining. The cavities are probably due 
chiefly to solution; their interiors are generally smooth, and when the 
rock is broken up a fragment resembles a very irregular nodule, the 
surface of which is partly smooth and partly rough and broken. 
Associated with the rock is a black sandy clay which contains a minor 
amount of small rounded phosphate nodules. 

The term nodule was applied by the earlier writers to the whole 
mass, and even the large pieces removed in mining were described as 
^ ‘made up of nodules cemented together.” Loosely scattered nodules 
are referred to by some of the older writers,^ however, and it is prob¬ 
able that the solvent action was sometimes strong enough to enlarge 
the cavities until the mass was actually broken up. Some of the 
fragments are described as coated with a hard and lustrous enamel, 
but so far as can now be ascertained such fragments were of the river 
variety. No instance of concretionary structure in land rock is men¬ 
tioned by any of the earher writers. Moreover, the rock contains 
many casts and molds of the same species that characterize the un¬ 
altered Edisto marl,2 and there seems little doubt that it is really a 
bed of irregularly phosphatized marl rather than a mass of con¬ 
cretionary nodules. 

The rock varies considerably in color, hardness, and specific gravity, 
these characters being partly dependent on the degree of phospha- 
tization. Much of the material now being mined is fight yellowish 
brown in color and is soft and chalky. AU variations in color from 
fight brown to very dark gray are exhibited, and as the color deepens 
the hardness and specific gravity increase. A dark rock generally 
contains more lime phosphate per unit volume than a fight-colored 
one and is therefore considered more valuable. 

The cavities in the phosphate rock are fiUed with sandy clay, which 
is generally calcareous and somewhat phosphatic. Its color appears 
to depend largely on that of the rock with which it is associated. In 

1 staler, N. S., On the phosphate beds of South Carolina: Boston Soc. Nat. Hist. Proc., vol. 13, pp. 222- 
235, 1870. 

2 Sloan, Earle, op. cit., p. 299. 




194 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

placGS this material contains quartz pebbles and pebbles or small 
nodules of phosphate rock. It also carries the abundant remains of 
many species of vertebrates which are not found within the rock mass 
itself. 

The river rock occurs generally in loose and more or less rounded 
fragments of nodular aspect, which have accumulated in irregular 
banks on the river bottoms. In many localities they are well rounded 
and are inclosed by hard lustrous enamel. Penrose ^ distinguishes six 
different varieties of the river rock by their color and the presence or 
absence of enamel. The river rock is generally darker in color than 
the common land variety, being dark brown or gray or even jet-black. 
It is higher in specific gravity than the ordinary land rock and is gen¬ 
erally harder, especially when inclosed by enamel. Some varieties 
are Mghly siliceous, the grains of sand being visible to the naked eye. 
According to Penrose some of the rock from BuU River exhibits a dis¬ 
tinct concretionary structure, but this is very uncommon. In Morgan 
River and elsewhere the river rock has been found in a thin and more 
or less continuous bed like that of the ordinary land deposits, but it 
generally occurs in thick but irregular banks. Some of these deposits 
are fairly free from mud and sand and yield a product wliich requires 
httle washing. In others the proportion of matrix is greater and may 
increase laterally until the phosphate is too sparsely scattered to allow 
mining. As would be expected in a river deposit, the distribution of 
the rock is generally very irregular, as is also the character of the over- 
lying and underlying material. Where the river rock occurs as a more 
or less continuous and undisturbed bed it appears to rest upon the 
Cooper marl, but in its more common reworked condition it is gener¬ 
ally separated from the marl by clay or sand. 

Some writers have differentiated a third type which they call marsh 
deposits. These occur in a bed similar to the ordinary land deposits, 
but have the dark color and higher specific gravity of the river rock. 
They represent merely the undisturbed phosphate bed which has 
undergone certain changes. (See p. 209.) 

The irregular deposits of phosphate and quartz pebbles known to 
the miners as the '^Flying Rock bed” (the Accabee gravels of Sloan) 
are derived from the reworldng of the original land deposits. They 
are chiefly of scientific interest, although at some places they have 
yielded a hmited amount of phosphate. 

1 Penrose, R. A. F.,jr., Nature and origin of deposits of phosphates of lime: U.S. Geol. Survey Bull.46, 
pp. 60-70, 1888. 



PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


195 


CHEMICAL COMPOSITION. 

The commercial rock varies greatly in phosphate content, but at no 
place does it contain more than 64 per cent in the washed but unburned 
condition. Waggaman^ states that isolated fragments have been 
found wliich contain as much as 75 per cent, but these do not occur in 
commercial quantity. Some of the rock mined in the Edisto district 
averages 62 per cent (see analysis 7, p. 196), but it is probable that the 
general average for the South Carohna area would approximate 58 per 
cent. There are many districts in which the phosphate content is as 
low as 55 or 53 per cent. 

According to Shepard,^ who made many hundred analyses of the 
South Carolina phosphate, the composition varies greatly in even one 
piece of rock. Thus the upper portion of the bed, which is generally 
flat and compact, is commonly somewhat higher in phosphate than 
the lower, more irregular, honeycombed portion. Similarly the exte¬ 
rior of a river nodule, especially when coated with enamel, may run 
2 per cent or more higher in phosphate than the interior. The com¬ 
position bf the rock from a broad district is naturally even more 
variable, and irregular areas are sometimes found in mining in which 
the rock is of too low grade to work. The composition of the average 
commercial product, however, is fairly uniform. 

In the following table are given fourteen analyses of the average 
commercial South Carohna product compiled from various sources, 
and three type analyses of the commercial Florida rock, inserted for 
comparison: 

1 Waggaman, W. H., Report on the phosphate fields of South Carolina: U. S, Dept. Agr. Bull. 18, 
p.6,1913. 

2 Shepard, C. U., jr., South Carolina phosphates, p. 21, Charleston, 1880. 



Analyses of phosphate rock from South Carolina and Florida. 


196 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 





4^ 


a 


a 

o 




a 

a 

C3 


a 

o 


u 

C3 


CO ^ 

-a 

o. ^ 

a w 

r o 
b£ 

o 




a 
o 

^ C3 

gS 

. -S 
a'^o .2 

rS ^ 
a—« 

O o3 O 

nqin I 

03 **-H pH 

a. .®Q 

!=! a ® 

slil 

_ w Jh O 

glp?^ 

+j o 

^ ti o 

fe-o-S V 
2 

- ^ 


o 

tX) 

tH 

c3 




.52 

tj 

t>i 

w 

a> 


P. 

a 

d 

tn 

<s> 

tuD 

C3 

CP 

t> 

c3 

o 

bO 

IH 

c3 


C3 


fl 

o 


® 

a 

a 

® 

a 

oT 

o3 

a 

a 

M 

o 

a 

a 


03 

•pH 

M 

O 

a 

a 

CO 

O 

a 

a 


a 

CO 

O 

a 

a 


i (N OC a lO ^ CO 

J t-H rH tH t—» 

a 


ric! . 
o-^ 

® s 

t-( 03 © 

? a^ 
b 

ig " ® 

.W.-ba . 

N O 


aa 
o 


a 


a 

o 



K *1—1 

a H ^ o 
-S N al 

H CP ^ ^ 

w O ^ 

P 


<a> jh 


CO 


O 


phx) a 

® ®!§^2° 
33.g-E§^;^ 

W C/3 Jd P o ^ 

<l<^owoa 


a 

CO 


c3 

a CO 
QrH 

a 

CO r 
® 433 
CO "r! 

"S a 
‘o’So 

“tr N d 

® «« S 

§30 2^ 

fe’d'd g 

> s-i »-3iS 
S o3 cSTS 

” a ato 

OJCCiCC! b 

> 2 
■u a 

p4 ^ 


o o 
o o 


CQ 

o ^ ^ 
CP'P'P aJ 

CP CP»^ 

^ o o 
'o "o 

CP CP 
c3 • » 

S p^ 

r1 rP Jm 
O W<C3 


a 

C3 

03 

O 

to 

(H 


4-5 

CP 


;p'p c3 


;h ^H 

■P O CP g 

'2p5«a 

^45 O O—! 
‘o.og c fi'd 

P^MCCl^ 


aoico'c^ioco+jf^oO'^S 



























































































PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 197 

« 

The analyses show that the percentage of phosphoric acid in the land 
rock is very uniform, ranging from 26.68 to 28.47, and that in the river 
rock it is generally lower, ranging from 22.36 to 27.26. The insoluble 
matter (chiefly sand) is generally higher in the river rock and reaches 
24 per cent in the Wando product, though it is only 9.06 per cent in 
the Coosaw River product. Chazal says that the river rock gener- 
. ally contains more organic matter than the land rock, and Shepard 
says that it contains less iron and alumina, but the above analyses do 
not establish these differences. Despite its lower percentage of phos¬ 
phate the river rock was strongly preferred in the early days of the 
industry, partly because of its low content of iron and alumina, which 
made it more attractive to the foreign trade, but chiefly because of the 
greater ease with which it could be mined and washed and because of 
its higher specific gravity, which meant a higher percentage of phos¬ 
phate per unit volume handled. The difference in grade between 
dark and light colored rock is illustrated by analyses 8 and 9, which 
respectively show 55.91 per cent and 58.24 per cent of lime phosphate. 
The land rock of the Ashley district (analyses 1 and 2) may be taken 
as the general type for the whole area and as closely representing the 
product now being mined; that of the Edisto district (6 and 7) is 
exceptionally good. The river rock of the Stono and the Coosaw 
(analyses 8, 9, and 11) constituted the bulk of the river rock mined, 
but it is somewhat higher in grade than that of the other rivers. 

In interpreting these analyses in a commercial way it must be 
borne in mind that most of them represent crude unburned rock or 
rock that has only been partly dried (air dried). In the calcination 
to which the rock is now subjected before it is sold the moisture and 
organic matter and part of the carbon dioxide are eliminated and the 
proportion of phosphate is generally increased 4 or 5 per cent thereby. 

The analyses given in the table indicate that the South Carolina 
product can not compete with the Florida rock in quality. The 
present guaranties for the Florida export product are 78 per cent or 
more of lime phosphate and 3 per cent or less of iron and alumina. The 
very highest grade specimen of the South Carolina rock probably does 
not contain as much as 80 per cent of phosphate and the customary 
export guaranty in 1880 was only 55 per cent.^ It later rose to 58 
per cent and is now 60 per cent, but this is nearly as high as the South 
Carolina field can be expected to average, although the product of 
the Edisto district would approximate 61 per cent. On the other 
hand, however, the South Carolina rock makes an excellent acid phos¬ 
phate which is in good mechanical condition for mixing purposes, and 
' many consumers are said to prefer it on the ground that it makes a 
better fertilizer. 

1 Shepard, C. U., jr., South Carolina phosphates, p. 16, Charleston, 1880. 

52639°—14-3 




198 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 


PERSISTENCE OF BED. 

In the fields and districts roughly defined below there are many 
small areas in which the phosphate bed is lacking or is too thin to be 
of value or is overlain by cover too thick to remove. Owing to the 
length of time over which mining operations have extended and to 
the large amount of phosphate already removed it is impossible to 
prepare a large map showing in detail the distribution of the workable 
rock. , Considerable prospecting has been done throughout the general 
area, however, and maps have been prepared showing the exact thick¬ 
ness and distribution of the phosphate in certain tracts. The accom- 



Figure 55. — Sketch map and sections showing irregularity of 

Stono River, S. C. 


phosphate stratum near north branch of 


panying map (fig. 55), which was kindly placed at the writer’s disposal 
by Mr. John Hertz, shows the irregularity of the phosphate stratum. 

The tract shown on figure 55 is located near the north branch of 
Stono River, or on the southern border of the Ashley-Cooper field, 
described below. The extent of the workable phosphate is shown on 
the map, and the thickness of the stratum is shown by sections at 
intervals of 400 feet, obtained in bore holes and test pits. The sections 
suggest that although in some places the phosphate decreases regularly 
in thickness and feathers out, in most places it breaks off abruptly. 
This general irregularity in the thickness of the stratum is probably 
typical of the whole area, although in places the average thickness of 
the rock is much greater. The irregularity is further emphasized by 
































PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


199 


the difference in average thickness of phosphate under the small areas; 
thus the average for the small area shown at the extreme left of the 
map is 12 inches, that for the small area shown near the bottom of the 
map is only SJ inches, and that for the largest area is 9 inches. An 
estimate based on these thicknesses shows that the average yield per 
acre in these areas would be 1,080, 316, and 675 tons, respectively. 
In the whole tract shown on the map the proportion of blank’’ 
area—that in which the Edisto marl is unphosphatized or is absent— 
is probably larger than that in most of the Ashley-Cooper field. Thus 
the area prospected is 926 acres, of which only 321 acres is underlain 
by phosphate rock, which averages 9 inches in thickness, whereas in 
a tract 1J miles to the east the 200 acres prospected proved to be all 
underlain by workable rock of an average thickness of lOf inches. 
On the other hand, however, random borings made at three localities 



Figure 56.—Sections showing depth of phosphate bed below surface along line E-E' on figure 55. 


several miles northeast of the first tract showed no phosphate within 
20 feet of the surface. 

In figure 56 are given ten sections measured along the line E-E' 
on figure 55 at intervals of about 360 feet. These sections show the 
depth of the phosphate below the surface to vary from 2 to 19 feet. 
Unfortunately, the absolute altitude of the surface along this line is 
not known, but a study of the drainage indicates that the variation 
in the depth of the stratum is due chiefly to the variation in its own 
altitude rather than to that of the land surface. This is to be expected 
because of the unconformable contact between the phosphate-bearing 
Edisto marl and the underlying Cooper marl, and affords a good 
example of the irregular and uneven character of the old surface on 
which the Edisto was laid down. In general this old surface is prob¬ 
ably much more level than is here indicated, but in some localities, 
notably along Edisto Kiver, its irregularity is even more pronounced. 

The unevenness of the old Cooper surface, as shown by figure 56, 
suggests that in some of the areas in which the phosphate bed is 













































200 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

thought to be absent it is merely covered by a greater thickness of 
overburden, and that it may therefore be somewhat more persistent 
than has hitherto been supposed. Owing to the fact that 20 feet is 
about the maximum thickness of overburden that can profitably be 
removed, the prospecting is generally carried only to this depth, and 
if the bed is not encountered it is reported absent. In some localities 
the operators can say with certainty that the old marl surface was 
reached, but in others the work done proves only that the phosphate 
bed does not lie within 20 or 25 feet of the surface. The presence of 
the bed at a greater depth has no commercial interest unless improved 
machinery capable of removing cheaply a greater thickness of cover 
is installed, but it is of distinct scientific interest in connection with 
the origin and geologic relations of the phosphate. 

DISTRIBUTION. 

All the commercially important deposits of phosphate rock lie on 
the seaward side of a rough arc drawn from a point near the source of 
Wando Kiver to the mouth of Broad Kiver. This area is approxi¬ 
mately that underlain by the Edisto marl; but, as stated above, the 
distribution of this formation is somewhat irregular and the rock 
varies considerably in phosphate content, in some places being prac¬ 
tically unphosphatized. Furthermore, in the course of mining opera¬ 
tions during the last 45 years the phosphate has been entirely removed 
from tracts many square miles in extent. It is therefore impossible 
accurately to define the workable phosphate-bearing areas and they 
can be referred to only in more or less general terms. 

On the map (PI. II), however, an attempt has been made to show 
approximately the distribution of the phosphate. This map is based 
on that compiled by Shepard in 1870, but is modified because Shep¬ 
ard included only those areas in which the rock is within about 6 
feet of the surface, whereas it has since been mined to depths of more 
than 15 feet. It must be borne in mind, however, that within the 
areas shown are many smaller districts in which the phosphate is 
lacking or is present at too great a depth to be workable, and many 
others, including practically all of the river deposits, in which it has 
been mined out. 

In a general way the area may be divided into five fields. The 
Wando field contains chiefly a river deposit of rather small extent, 
which is now mostly worked out, but which has yielded a large quan¬ 
tity of fair-grade rock of the nodular form, black color, and high spe¬ 
cific gravity characteristic of the river rock. Small areas of land 
rock occur along Wando Kiver, but attempts to mine them have been 
unsatisfactory. 


PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 201 

Northeast of the Wando field is the Cooper field, containing both 
land and river rock. The rock in this locality is of rather low grade 
and very little of it has been mined. 

The Ashley field, a short distance northeast of Charleston, com¬ 
prises about 150 square miles and is the largest and most important of 
all. The best deposits lie in the district along Ashley River and as far 
south as Rantowles Creek and Stono River. This district has been 
under continuous development since 1868 and has furnished by far 
the largest output of the land rock, having been practically the sole 
producer in South Carolina since 1904. The deposits on the western 
edge of this district are of less value than the rest, being thin, irregu¬ 
larly phosphatized, and in many places under considerable cover. 
Farther down the river, however, the rock is uniformly good, and the 
overburden is very regular in thickness over large areas. On the 
north side of Ashley River the workable phosphate has been largely 
mined out, but between it and Rantowles Creek large deposits still 
remain. In the district along the Atlantic Coast Line Railroad, espe¬ 
cially near Mount Holly, a considerable amount of mining has been 
done. The best deposits are probably exhausted, for much of this 
area is known to be underlain by deposits which are poor or variable 
in character and irregular in extent. This is especially true in the 
district along Black and Cooper rivers, in which very little mining 
has been attempted. 

The Stono River district, along the southern edge of the Ashley- 
Cooper field, has produced considerable quantities of river rock, 
which was of fairly high grade but which was mixed with marl and 
shells that were difficult to separate. Some of the earliest river min¬ 
ing was done on Stono River, and although the best deposits have 
been removed, it is possible from the more or less Rregular character 
of the mining that some workable phosphate still remains. 

Tlie area west of Rantowles Creek almost as far as Edisto River is 
barren of workable phosphate, although thin deposits have been dis¬ 
covered at several places. Along the east bank of the Edisto a little 
north of the railroad a considerable amount of mining has been done, 
but it is reported that valuable deposits still remain.^ Farther up the 
river on the east bank the rock is fairly thick and is easily accessible 
but is of rather low grade. River deposits occur in the Edisto itself 
but are so irregular that practically no mining has ever been done. 
The most important district of the Edisto field is that lying between 
Edisto and Ashepoo rivers, where many deposits of uncommonly 
high grade rock have been worked. According to Chazal some of the 
rock mined in this district contained as much as 64 per cent of lime 
phosphate and owing to the uniform thinness of the overburden was 


1 Chazal, P. E., Sketch of the South Carolina phosphate industry, p. 5,1904. 




202 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

very easy to mine. The rich deposits are irregular in extent, how¬ 
ever, and there are many small areas in which the phosphate content 
is rather low. The chief obstacle to the thorough development of 
this district has been its relative inaccessibility, in consequence of 
which many fairly rich areas remain untouched. 

The Coosaw field marks the southern extremity of the general 
phosphate area. Land deposits in this field are confined to the 
islands inclosed by Coosaw, Bull, Morgan, Johnson, and Beaufort 
rivers, and smaller channels. Owing to the somewhat inferior char¬ 
acter of the rock and to the irregularity of the overburden these 
deposits have never been very extensively worked. By far the 
largest part of the great output of this field was obtained from the 
river deposits of the Coosaw and its smaller connecting channels. 
The deposits of the Coosaw itself covered 12 square miles with an 
average thickness of 22 inches and consisted of high-grade rock; ^ 
they apparently represent the concentration of the land deposits of 
a considerable area. Along the sides of the channels they grade into 
marsh deposits which were also extensively worked. The rock of 
Morgan River is also reported to have been high grade, and to have 
occurred in part as a layer 15 inches thick, similar to the land deposits. 
The phosphate of this district had been largely worked out by 1900, 
although some mining continued in the Coosaw itself until a few 
years later. The river deposits of Beaufort, Broad, and Johnson 
rivers are somewhat inferior in grade and have not contributed very 
extensively to the production. 

QUANTITY. 

Owing to the very irregular distribution of the South Carolina 
phosphate it is impossible to make an accurate estimate of the amount 
still available. Very little prospecting was done in the early days of 
the industry and although in recent years a large amount of explora¬ 
tion work has been done there are still many large areas concerning 
which the information is only approximate. 

Shepard, in 1880, estimated the total available supply to be less 
than 5,000,000 tons, but over twice that amount has already been 
mined. Chazal, in 1904, estimated the supply still available at be¬ 
tween 9,000,000 and 11,000,000 tons. Since that time less than 
2,000,000 tons has been mined, which, according to this estimate, 
leaves between 7,000,000 and 9,000,000 tons. Some of this is under 
rather heavy cover and can not be mined at the ordinary cost, but 
much of it is probably comparable in accessibility and quality to that 
successfully mined in the past. The bulk of this phosphate is of the 
land variety, and is located in the areas between Ashley River and 
Rantowles Creek and between Edisto and Ashepoo rivers. 


1 Millar, C. C. H., Florida, South Carolina, and Canadian phosphates, p. 156, London, 1892. 





PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


203 


ORIGIN. 

EARLIER THEORIES. 

All previous observers have advanced theories of the origin of these 
phosphate deposits, but all the theories except Sloan’s were founded 
on what now appears to be a misconception of the geologic relations 
of the deposits. However, the essential idea of most of the earlier 
wiiters, namely, that the phosphate deposits are due to a concentra¬ 
tion of the phosphate disseminated through the Cooper marl, is 
probably correct, although more geologic work is required before any 
hypothesis can be definitely accepted or rejected. Before reviewing 
the earlier theories it may be well to reiterate that the phosphate 
deposit is not essentially a collection of nodules, but is rather a more 
or less continuous bed of Miocene age, which is irregular in thickness 
and honeycombed by cavities, and is in places found unphosphatized. 
(See p. 193.) 

Pratt advanced the earliest theory, which ascribed the phosphate 
to the accumulation of bone and the other remains of vertebrate 
animals. This material, he thought, had accumulated somewhere 
in the central part of the State and after the soluble portion had been 
leached away and the whole mass consolidated it was brought to its 
present position by streams. The mechanics of the consolidating 
process is not clear, nor the method by which the mass could have 
been transported by streams and laid down as a fairly pure bed. 

Holmes in 1870 advanced a theory, which was generally accepted at 
that time, based on the view that the bed is a collection of nodules. 
According to Holmes the old surface of the Eocene marl was submerged 
and numerous fragments were broken off by the waves and deposited 
in irregular basins below sea level. After the elevation of the land the 
sea water caught in these basins evaporated, leaving salt licks, which 
were visited by numerous land animals. These animals deposited in 
the basins their fecal, remains, bones, and bodies, and the phosphoric 
acid derived from this mass of organic matter later replaced the 
carbonate in the underlying bed of marl nodules. The chemistry of 
this reaction is well established, but it is difficult to understand the 
regular deposition of the ^^marl nodules” themselves or their con¬ 
version into a fairly continuous bed. Moreover, this theory is re¬ 
futed by the fact that the phosphate fragments are rich in Miocene 
fossils, whereas the underlying marl contains Eocene fossils in much 
smaller numbers. 

Shaler in the same year (1870) advanced a theory which is much 
more reasonable geologically and which fundamentally is probably 
correct. According to Shaler the phosphate rock is a residual crust 
formed by the gradual removal of the underlying marl, the carbonate 


204 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

having been carried away in solution while most of the phosphate 
remained in place. The phosphate bed would therefore be merely 
the topmost layer of the Eocene marl. That the theory as stated is 
not entirely adequate is indicated by the Miocene fossils in the phos¬ 
phate. 

Shepard in 1880 accepted the nodule theory of Holmes, and Pen¬ 
rose in 1888 followed Shaler. 

Levat in 1895^ stated that the phosphate was formed “by the 
transportation, after disaggregation, of the phosphatic Eocene marl 
and its deposition in a shallow Miocene estuary together with a 
variable proportion of sand and clay.” He also emphasizes the fact 
that the bones associated with the phosphate could not have supplied 
the phosphoric acid, for they themselves contain more than the 
normal amount. 

/ 

Chazal in 1904 propounded a theory essentially like that of Holmes. 
He believed that fragments of the Eocene marl were torn from the 
old surface by tidal action and were later subjected to the action of 
solvent waters, which dissolved away the carbonate and replaced it 
with phosphate. After formation the nodules “were caught up and 
transported by the agency of the enormous tides of the post-Pliocene 
seas and deposited in valleys, hollows, or old waterways.” Aside 
from the somewhat unusual nature of this transportational process, 
the presence of Miocene fossils in the phosphate is incompatible with 
this theory. 

Sloan in 1908 was the first observer, with the possible exception of 
Levat, to take into account the true geologic relations of the deposit. 
According to Sloan the land surface (Cooper marl) was submerged 
in Miocene time and the Edisto deposited on it as an unphosphatized 
mail. After the deposition of the Edisto, phosphatic sediment was 
laid down upon it, which ultimately phosphatized it. The phos¬ 
phatic sediment was derived chiefly from the disintegration, partial 
solution, and erosion of the Cooper marl, but also from phosphatic 
organisms stranded on the coast by the Gulf Stream, and to a lesser 
extent from bones and other remains which accumulated after the 
coast was elevated above sea level. However, as the Edisto in its 
unphosphatized condition must have been formed of sediment 
derived from the Cooper marl, it is difficult to understand why so 
much phosphatic sediment was brought down from the same land 
surface immediately after its deposition. Furthermore, it seems 
probable that the leachings of this old surface were chiefly calcareous, 
and that the phosphate, being coarser, remained to a considerable 
extent as a residual soil, according to ShaleFs view. 


1 Levat, David, Industrie des phosphates et superphosphates, p. 83, Paris, 1895. 






PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 205 

RESIDUAL-SOIL THEORY. 

The writer’s theory differs somewhat from any hitherto formulated, 
although involving the central idea of several of the earlier views. 
The fact that the phosphate is not a collection of Eocene nodules 
vitiates the arguments of Holmes, Shepard, and Chazal. Shaler’s 
theory is similarly injured; for, as the Edisto is known to be marine 
Miocene, it must have been deposited during a distinct period of sub¬ 
mergence. Sloan’s hypothesis is unsatisfactory to the writer in that 
it involves the derivation of unphosphatized marl from an old land 
surface and a later derivation of richly phosphatic sediment from the 
same source. Levat’s theory is not clearly expounded, but seems to 
approach most closely to the views advanced below. 

The general conditions of sedimentation in this area have already 
been set forth. (See p. 191.) It seems certain that the Cooper marl 
formed a land surface during much of Oligocene and early Miocene 
time, and during this period it must have suffered considerable 
weathering and erosion. As this surface was not far above sea level, 
the amount removed by actual stream erosion was probably small in 
comparison with that lost by leaching and solution. The analyses 
given below show that the Cooper marl contains a certain amount of 
phosphate, which is in part disseminated through it in the form of 
grains and in part more irregularly distributed as nodules and to a 
minor extent as bone fragments, and probably also as phosphatic 
shells and sharks’ teeth. As the Cooper land surface was gradually 
worn down, much of this coarser and more insoluble phosphatic 
material probably accumulated as a residual soil, only a part of it 
being carried away as sediment. Sloan ^ estimates the average phos¬ 
phate content of the upper part of the Cooper to be 3 per cent (see 
analyses, p. 208), which gives 121 tons of 60 per cent phosphate rock 
per acre-foot. In other words, the disintegration of 8 feet in every 
acre of Cooper marl would yield about as much phosphatic material 
as is contained m an average acre of the phosphate bed. As a matter 
of fact, much of this phosphatic material was doubtless carried away 
as sediment; but, on the other hand, it is probable that many times 
8 feet of Cooper was disintegrated and partly removed during the 
long period in which it remained above the sea. It may safely be 
assumed, therefore, that at the end of early Miocene time the old 
Cooper land surface was covered with a residual soil which was prob¬ 
ably highly phosphatic in many places, though much less so in 
others, owing to the irregular distribution of the phosphate in the marl 
from which the soil was derived. 


1 Sloan, Earle, op. cit., p.333. 



206 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

At the end of early Miocene time the region was depressed some¬ 
what below the sea and, as indicated by the present topography and 
the distribution of the phosphate bed, became a great estuary or 
series of estuaries. As the water gradually encroached on the land 
the residual soil was disturbed by wave action and much of the 
intermixed vegetal debris removed. The areas in which the Edisto 
is lacking to-day were probably partly submerged islands on which 
wave action was sufficient to wash away the residual soil. The relief 
of the old surface was probably not great, however, and if certain 
areas were left liigh enough to form islands, it seems that the depres¬ 
sion was jiot a great one and that the general surface was not covered 
with very deep water. W. C. Kerr ^ suggests that phosphatic bi¬ 
valves whose shells were later broken up by wave action may have 
contributed phosphate. As an example, he points out that the shells 
of Lingula lyyramidata, which are still found in large numbers along 
the coast, contain about 55 per cent of lime and magnesian phosphate. 
W. H. Dali, however, stated to the writer that in his opinion neither 
this organism nor any of the other phosphatic brachiopods were pres¬ 
ent in sufficient numbers in Miocene time to have enriched the 
deposit materially. At this time also fishes, amphibians, and rep¬ 
tiles flourished along the coast, and their fossil remains, which are 
now found m great numbers, probably added somewhat to the supply 
of phosphate. In addition to these sources, a certain amount of 
sediment was being received from the land during this period, and 
this probably also contained some phosphate. By the end of middle 
Miocene time, when gradual reelevation of the coast began, a deposit 
aggregating 5 to 10 feet thick had probably accumulated. This 
deposit was in general richly phosphatic, but the phosphate was prob¬ 
ably distributed through it irregularly and in some places was present 
only in minor amount. 

The reelevation of the land progressed until most of the areas now 
underlain by phosphate became a series of marshes, in which it 
seems certain, as Shepard, Shaler, and Chazal contend, a chemical 
alteration of the phosphatic marl (Edisto) would take place. The 
most extensive alteration would be the leaching out of the carbon¬ 
ate of the marl by carbonated waters, leaving most of the phosphate 
intact, and this process would ultimately result in converting the 
original 5 or 10 feet of Edisto into a thin but higlily phosphatic crust. 
Concomitantly with this process, however, a partial replacement of 
carbonate by phosphate took place. Keese^ has shown that swamp 
water readily dissolves phosphate, but that the phosphate is repre¬ 
cipitated when the water stands in contact with lime carbonate. 


1 Am. Naturalist, vol. 4, p. 571, 1871. 

2 Reese, C. L., On the influence of swamp waters in the formation of the phosphate nodules of South 
Carolina: Am. Jour. Sci., vol. 43, pp. 402-406, 1892. 





PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


207 


This would also tend to concentrate the phosphate at the bottom of 
the Edisto, where the waters came in contact with the purer under¬ 
lying marl, and would furthermore tend to destroy the original forms 
in which the phosphatic material was scattered through the Edisto. 
The original Edisto marl was thus largely removed by solvent action, 
but most of its phosphatic material, chiefly in a reworked condition, 
was retained. Eeptiles and amphibians continued to flourish during 
this period and in addition a few land animals frequented the marshes. 
Their bones are found to-day on the phosphate bed and intermingled 
with it but not actually incorporated in the mass. These bones 
have themselves been phosphatized, perhaps in part through the 
agency of other bones now entirely dissolved, and probably only a 
minor amount of the phosphate in the Edisto itself can be attrib¬ 
uted to these remains. 

The theory above outlined seems to account for all of the known 
facts. The presence of a few worn Eocene shells in the phosphate is due 
to its derivation in part from the residual soil. The presence of the 
rich marine Miocene fauna is accounted for by the submergence of the 
old surface during the Miocene. The vertebrate remains, which are 
Pliocene, Pleistocene, and Kecent, are evidently later than the forma¬ 
tion of the phosphate itself. According to this view, the black 
sandy clay which fills the cavities of the phosphate rock and in which 
many of the vertebrate remains are found, is also later than the 
phosphate. The originally irregular distribution of the phosphate, 
which was probably further increased by its later solution and 
reprecipitation, seems to explain the fact that the bed now varies 
. greatly and rather abruptly in thickness. It also throws light 
on the fact that the phosphate bed is not generally thicker in the 
depressions of the old surface but appears to vary irregularly. 
The supposition that the Edisto as originally deposited was much 
thicker than the present phosphate bed is borne out by the fact that 
in the unaltered condition it is generally 4 or 5 feet thick, according 
to Sloan. The areas in which .it is thus found were presumably 
islands in the old marsh where it was not subjected to the leaching 
and concentrating process, and the areas in which the Edisto was 
entirely lacking probably represent wave-swept islands in the estu¬ 
aries in which the formation was deposited. This idea is partly 
borne out by the fact that the Edisto is lacking or is unphosphatized 
on the higher portions of the present interstream areas, as, for example, 
on that between Rantowles Creek and Edisto River and between the 
Ashepoo and the Combahee. 

The experiments of Reese indicate that the leaching and concen¬ 
trating process is possible, and that it has actually taken place is 
strongly suggested by the irregular shape of the phosphatized mass. 
Moreover, the Cooper marl immediately beneath the Edisto generally 


208 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 


contains about 15 per cent of phosphate and for a distance of almost 
30 feet commonly shows some enrichment. Below this the percent¬ 
age of phosphate varies but seems to average about 3 per cent. The 
enrichment of the marl beneath the phosphate has been noted by 
several observers and is well shown in the first four analyses given 
below; the general composition of the marl at other, and probably 
lower, horizons is shown by the last six analyses. 


Analyses of the Cooper marl. 


- 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

Si 02 (and insoluble).... 


8.56 

15.45 

15.61 

12.80 

37 06 

17.13 

21.14 

15.04 

*^1 77 

AI 2 O 3 . 


1.11 

1.88 

2.74 

1.34 

^83 


F 6203 . 


.95 

.95 

1.10 

.79 

1.38 




1 11.75 

Na 20 . 





.35 

.29 




K 2 O. 





.32 

.39 





MgO. 

0.65 


.31 

1 20 

43 

3 91 

Undet. 

c;a 



CaTO. 

29.44 

48. 80 

43.41 

41.80 

45.68 

26 80 

33.76 

43.52 

. ^0 
39.80 

SO 3 . 

.58 



.34 


P 2 O 5 . 

7.00 

4.13 

1.76 

.45 

1.29 

3.03 

3.01 

1.26 

10.65 

2.98 

CO 2 . 

16.29 

34.50 

32.79 

33. 74 

35.17 

21.88 

26.64 

24. 78 

15.67 

8.32 

Ignition. 


.62 

1.68 

1.31 

.91 

1.65 




1 80 

Moisture. 


1.19 

1.29 

2.46 

.96 

2.07 




.25 











99.86 

99.52 

100.41 

100.04 

99.63 





Equivalent Ca 3 (P 04 ) 2 .. 

15.28 

9.02 

3.85 

.98 

2.82 

6.62 

6.57 

2.74 

23.24 

6.51 

Equivalent CaC 03 . 

37.04 

78.41 

73. 77 

73.70 

78.85 

40.99 

60.54 

56.32 

44.70 

18.89 


beneath phosphate bed; Bees Ferry, Ashley River. Sloan (op. cit., p. 385). 
below phosphate bed; average sample; Ashley works, Ashley River. Sloan (op. cit., 

p, uo4j. 

3. Marl 10 to 28 feet below phosphate bed; average sample; Ashley works, Ashley River. Sloan (idem). 

4. Marl 28 to 50 feet below phosphate bed; average sample; Ashley works, Ashley River. Sloan (idem). 

5. Average Cooper marl, exact horizon unknown; Steep Blufl, Biggin Creek. Sloan (op. cit., p. 386). 

6. Average Cooper marl, exact horizon unknown; near Saxon, Goose Creek. Sloan (op. cit., p. 387). 

7. Marl 34 feet below surface at Sineaths station. Chazal (op. cit., p. 26). 

8. Marl 85 feet below surface at Sineaths station. Chazal (idem). 

9. Marl containing phosphate nodules, 110 to 112 feet below surface at Sineaths station. Chazal (idem). 

10. Average Cooper marl, exact horizon unknown; quarry at Woodstock (privately communicated). 


Samples 1, 2, 3, and 4, taken at successively greater depths below 
the phosphate bed, show a gradual decrease in phosphoric acid. This 
would be expected from the experiments of Reese, which show that 
lime phosphate is precipitated slowly when in contact with lime car¬ 
bonate. Owing to the moderate proportion of carbonate in the Edisto 
when it was first elevated above the sea and to the fact that this salt 
was constantly being removed by leaching and the proportion of 
phosphate thus increased, it is probable that phosphatic solutions 
were soon able to move freely in the mass. At first these solutions 
were weak because of the mass action of the carbonate present, and 
the phosphate was easily precipitated along the upper surface of the 
Cooper. With continuous decrease in the Edisto carbonate, how¬ 
ever, the solutions increased in strength, were less easily precipitated, 
and finally penetrated some distance into the underlying Cooper before 
all of their phosphate was removed. The enrichment of the Cooper 
in phosphoric acid is well shown by analyses 1 and 2, of samples 
taken within 10 feet of the phosphate bed. Analyses 3 and 4, of sam¬ 
ples taken between 10 and 50 feet below, show a decrease, 3 appar- 
























































PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


209 


ently representing about the original average composition of the marl, 
and 4 being abnormally low in phosphate. 

The exact horizons of samples 5 and 6 are not known. They may 
represent the true average composition of the Cooper, but analysis 6, 
especially, shows a high proportion of phosphate, which is probably 
due to secondary enrichment. Samples 7, 8, and 9 were taken from 
the deep well at Sineaths station described above (p. 187); but their 
horizons are not stated by Shepard, and it is possible that sample 7 
has undergone some enrichment. Sample 8 must be more than 50 
feet below the phosphate bed, however, and probably represents the 
general average composition of the marl. Analysis 7 is of interest, as 
it shows the composition of one of the more highly phosphatic layers 
of the Cooper. The horizon of sample 10 is unknown, but as the 
phosphate bed is not present in the immediate locality from which it 
was taken the marl has probably not been directly enriched. It is 
difficult to ascertain the original average composition of the marl 
where not secondarily enriched, but it seems certain that it contains 
an average of at least 3 per cent of phosphate and is thus abundantly 
able to have contributed extensively to the formation of the Edisto. 

The physical and chemical characters of the marsh and river depos¬ 
its seem also to accord with the theory above outlined. The marsh 
deposits occur in a bed like the ordinary land deposits, but the rock is 
generally somewhat higher in specific gravity and is darker in color. 
As is generally the case, the darkest rock is commonly the richest in 
phosphate and the marsh deposits as a whole consist of high-grade rock. 
This is explained by the fact that it has been subjected to the action 
of swamp water longer than the land rock and that therefore the con¬ 
centrating process has been longer continued. The result is a rock 
that is more compact and is richer in phosphate than much of the land 
rock. The darker color seems to be due chiefiy to the inclusion of 
more carbonaceous matter during the longer period of association 
with swamp water. The color is therefore not directly connected 
with the phosphate content, but is nevertheless an indirect indication 
of it, for it is a rough measure of the length of time during which the 
concentrating process has gone on. Similarly the river deposits are 
darker and higher in specific gravity, although generally lower in 
phosphate, owing to the intermixture of sand. The rounded character 
of the fragments of river rock is doubtless due partly to the mechan¬ 
ical but chiefly to the solvent action of running water. 

PHOSPHATE INDUSTRY. 

PROSPECTING AND MINING METHODS. 

Land mining .—Extensive prospecting and exploration work has 
been done in this area during the last 25 years, and it is reported that 
the location and extent of all of the workable deposits are known. 


210 CONTKIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

Much of this work has led only to outlining the deposits and gaining 
some idea of their thickness and the grade of the rock, but a great 
deal of detailed prospecting has also been done. Thus in the area 
shown on figure 55 (p. 198) one bore hole was sunk in each half-acre 
tract, or at intervals of less than 200 feet, and these were supplemented 
by a number of test pits. The information thus obtained affords a 
means of making a fairly accurate estimate of the quantity of minable 
phosphate in the ground in this area. 

The greater part of the exploratory work has been done by boring 
with a long rod or auger or with a pipe. The auger used is an octag¬ 
onal steel rod with a sharp point and a small shoulder just above the 
point. This rod is worked down through the unconsolidated sand and 
clay (see fig. 56) until it reaches the hard phosphate layer, when the 
distance traversed is measured. The rod is then forced through the 
phosphate layer into the soft marl below and is then withdrawn until 
the shoulder catches on the bottom of the hard layer. Another 
measurement is made, and the difference between the two gives the 
thickness of the phosphate. For more accurate work some operators 
use a 4^-inch pipe, which takes a core of rock that may be weighed or 
analyzed. 

Mining is now done entirely by steam shovel, hand labor being 
impracticable where the overburden is thicker than about 8 feet. 
The tract to be mined is firs.t thoroughly prospected, and m some tracts 
levels are run and drainage ditches are dug. Along one edge of the 
tract a canal about 20 feet wide and of sufficient depth to remove all 
the material above the phosphate is dug by a dredge or steam shovel. 
The dredge is, of course, preceded by a gang of laborers to clear the 
timber and blow out the stumps. The canal is extended in a straight 
line to the border of the property, the material removed being piled 
up on one bank and a movable steel track laid on the other. The 
phosphate layer is generally broken and dug with pick and shovel and 
thrown into buckets operated by a hoist that runs on the track and 
dumps the phosphate into flatcars. Some companies, however, remove 
the rock by a second steam shovel, of the clamshell type, which follows 
immediately behind the dredge. By the use of this second shovel the 
phosphate is broken up, hoisted, and loaded on cars in one motion, 
and hand labor is almost entirely dispensed with. It is said that one 
of these machines can load as many as 21 flat cars a day, although the 
average work of a machine is to load about 18 cars. Unless a system 
of lateral drainage ditches is developed one or two steam pumps are 
necessary to keep the canal dry, and these commonly follow the second 
shovel. When the border of the tract is reached the dredges are 
turned and a second canal immediately adjacent to the first is exca¬ 
vated, the overburden being thrown over into the old ditch. By this 
method practically all the phosphate is removed, and large areas that 


PHOSPHATE DEPOSITS OF SOUTH CAEOLINA. 211 

can not be mined by hand have thus been completely worked out. 
The marsh deposits are mined in a similar way, except that banks or 
levees are generally constructed to keep out water at high tide. 

Hand mining can be practiced only where the overburden is less 
than 8 feet, and, as the more accessible deposits have been largely 
exhausted, very little hand work has been done during the last few 
years. Such work is generally performed on contract, the price being 
paid for the rock delivered at the washer. The contractor generally 
sublets to the laborer, assigning each man a section of about 18 feet 
along the sides of a common canal, from which he removes the over¬ 
burden and digs and loads the phosphate. 

River mining .—River mining was extensively practiced in the early 
days of the industry, but steadily declined after 1887 and practically 
ceased about 1904. (See p. 219.) The first river mining was done by 
hand in deposits that were nearly or quite uncovered at low tide. 
Shepard states that large quantities of rock were mined in this way, 
though the favorable deposits were few. In somewhat deeper water 
oyster ‘tongs were used, especially on Wando River; and a small 
quantity of the rock was even dislodged and brought up by divers. 
The deposits in water sufficiently shallow for hand mining were soon 
exhausted, however, and steam dredges were introduced. The ear¬ 
liest models were adapted to working in water less than 20 feet deep, 
but with the exhaustion of the more accessible deposits the dredging 
was continued into deeper water until, according to Sloan, an extreme 
hmit of 52 feet was reached. In most of this mining the clamshell 
type of dredge was used, but at least one large bucket dredge, carrying 
38 buckets with a capacity of one-third ton each, was successfully 
used on Morgan River, where the rock occurred in a hard, compact 
layer. Much of the river rock occurs in more or less irregular banks, 
however, and some of the rock is probably overlooked. The tendency 
to dredge only the richest part of the deposit was strengthened by the 
practice of some of the companies of offering the dredge captain a 
bonus for a weekly production above a certain figure.^ Most of the 
river mining was therefore very irregular and showed a marked con¬ 
trast with the land mining, much of the river rock being lost. 

PREPARATION OF THE ROCK. 

After mining, the land rock must be washed and burned before it 
is shipped. As received from the dredge the phosphate is mixed 
with wet sand and mud derived partly from the overlying and under¬ 
lying material, but chiefly from the stiff sandy clay which fills the 
cavities in the rock itself. It is reported that in the early days of 


1 Millar, C. C. H., op. cit., p. 162. 



212 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

the industry the rock was picked over by hand and scrubbed with a 
brush in some convenient creek and that the resultant product was so 
impure that the land rock acquired a bad reputation and was long 
regarded with disfavor. 

Hand washing was soon discarded as entirely inadequate and 
mechanical washers were introduced. At present the work is done 
almost entirely by machinery. The product is received on flat cars 
from the dredge and scraped off into a hopper that discharges into a 
mechanical conveyor. The conveyor buckets empty automatically 
into a crusher, where the rock is partly washed and is broken into 
fragments. It is then delivered through a trough to the lower end 
of a cylinder washer. This washer is a cylinder 27 feet long by 5 
feet in diameter and is tilted so that the discharge end is a foot or 
more higher than the receiving end. The interior of the cylinder is 
fitted with plates arranged in the form of a spiral, so that as the cyl¬ 
inder revolves the phosphate is carried forward to the upper end. A 
stream of water under a pressure of 60 pounds enters the upper end 
of the cylinder and plays against the advancing phosphate, washing 
the finer material toward the lower end. This finer waste passes out 
through a heavy screen into a trough, through which it is carried by 
the water to the waste heap. The clean phosphate is discharged 
through the upper end of the cylinder onto a belt which transports it 
to the wet bins. While on the belt it is generally picked over by hand 
and any clay balls or fragments of marl are removed. 

Much phosphate is lost in this grinding and washing. The opera¬ 
tors estimate that 60 per cent of the material mined is sand, clay, and 
finely divided phosphate which escapes through the screens. Wagga- 
man ^ says that an analysis of the material on the dumps showed 
about 13 per cent phosphate of lime, which is almost 8 per cent of 
the product as mined, or 20 per cent of the phosphate actually uti¬ 
lized. This may probably be taken as an average, though some phos¬ 
phate deposits near Tenmile Hill are said by Chazal to be so friable 
and easily pulverized that a very large proportion is lost in handling 
and washing. 

After washing, the rock is dried before being shipped in order to 
take advantage of the very material reduction in weight. In the 
early days of the industry the drying was accomplished by piling the 
rock in bins over perforated pipes carrying hot air, or in some places 
merely by exposure to the sun. The latter method was wholly inade¬ 
quate and the former was only partly satisfactory, for 2 per cent or 
more of the moisture as well as most of the organic matter and carbon 
dioxide were still retained. Some operators, therefore, built expensive 
brickkilns in which the rock could be thoroughly calcined, but it was 


1 Waggaman, W. H., op. cit., p. 9. 



PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 


213 


later found that these were unnecessary and that the rock could be 
satisfactorily burned over cordwood in open sheds. The present 
practice is, therefore, to pile the rock over ricks of cordwood, 6 cords 
being allowed for 100 tons of rock. The heat generated by the com¬ 
bustion of the wood is increased by that of the organic matter in the 
rock and also by the formation and combustion of water gas, so that 
the rock is popularly said to ^'burn itself.’’ By this process the 
moisture content of the rock, which, after washing, is from 10 to 15 
per cent, is reduced to about 0.5 per cent, and the organic matter 
and part of the carbon dioxide are also expelled. The burned rock is 
soft and easily ground and is light gray, yellow, or red. 

The river rock was purified in a somewhat different manner. Ac¬ 
cording to Shepard, a lighter accompanied each dredge and all the 
washing was done before the material was taken ashore. The dredge 
emptied the rock directly into a conical washer, where it was cleaned 
by heavy streams of water. After leaving this conical washer the rock 
entered a crusher, through which it passed into a cylindrical washer 
for the final cleansing. This cylindrical washer discharged upon a 
second lighter on which the rock was towed ashore. The procedure 
varied somewhat according to the character of the rock and in many 
cases the first washing and the crushing were omitted. Owing to the 
more compact form of the river rock, many operators considered cal¬ 
cination unnecessary and dried it by hot air. 

After the final drying the rock is shipped in closed cars—in former 
years it was shipped by vessel—to the fertilizer factories. After it 
has been calcined it is easily ground and is then mixed with sulphuric 
acid to produce an acid phosphate. The customary specification is 
16 per cent soluble phosphate, although it is reported that a special 
method has been used to some extent by which a very high grade 
or double superphosphate is made. It is then generally mixed with 
calcined and finely ground marl, which acts as a base or filler and 
also as a drying agent, and with tankage, bone, potash, and ammonia 
salts, etc., in proportions which are varied according to the grade of 
fertilizer desired. 

ECONOMIC FACTORS. 

Workahility .—In the South Carolina phosphate field, as in most other 
producing mineral fields, the gradually increasing cost of productionhas 
been met by the introduction of machinery and of improved methods 
of mining. Thus, in the early days of the industry, it was not con¬ 
sidered practicable to remove an overburden of more than 6 feet on 
land or to dredge in water more than 15 feet deep. Yet in the last 
10 years as much as 22 feet of overburden has been profitably 
removed, and river rock has been dredged from a depth of 52 feet, 
including a cover of 16 feet of sand and mud. It is thus difficult to 


214 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

define a workable deposit, especially at the present time, when the 
competition of the Florida and Tennessee rock prohibits the mining 
of deposits which 10 years ago were considered very favorable. 

The most important factors are, of course, the thickness of the 
overburden and the thickness and compactness of the rock stratum. 
Under the conditions which have prevailed during the last decade 
15 feet of overburden may be removed without excessive cost, but a 
greater thickness must be offset by an exceptionally high yield of 
phosphate. The amount of overburden that can profitably be 
removed also depends somewhat on the natural drainage of the prop¬ 
erty, for this affects the extent to which steam pumps must be used. 
The yield of the phosphate itself depends not only on the thickness 
of the stratum but also upon its compactness and its hardness. 
Other conditions being equal a 12-inch stratum is good, and a 10 
or even an 8-inch stratum can be profitably worked. In some places, 
however, the cavities in the phosphate are exceptionally large and 
may reduce the yield of a 12-inch stratum below the workable limit. 
In some localities the rock is so soft and friable that it can not stand 
transportation and washing, for even the hardest rock generally 
suffers in the washing process. When the stratum is exceptionally 
thin its hardness may be very important, because the heavy dredge 
travels directly on it and must use it as a floor. 

The composition of the rock is also important. The guaranty of 
lime phosphate has steadily risen from 55 per cent in 1880 (Shepard) 
to 60 per cent at the present day. Tliis rise is not absolute, however, 
and has been largely met by improved methods of preparing the rock. 
Under the present method of calcining the rock nearly all of the mois¬ 
ture and organic matter and part of the carbon dioxide are eliminated, 
so that a rock which would have yielded 55 per cent under the old 
conditions of washing and air drying may now yield over 60 per cent. 
Even with this improvement in methods, however, the rock at many 
localities, especially along the northern and western borders of the 
fields, is too low in phosphate to be marketed under the present 
guaranty. 

Cost of production .—Notwithstanding the extension of the workable 
deposits brought about by improved methods the industry has suffered 
seriously because of the increasing cost of production. The great 
increase in the price of labor and the exhaustion of the shallower 
deposits have practically put an end to hand mining. In consequence 
an elaborate and expensive plant is now necessary and the small 
operators have been forced out of the business. 

Waggaman^ estimates that under average conditions, when the 
plant is working to its full capacity, the cost per ton of mining. 


1 Waggaman, W. H., loc. cit. 



PHOSPHATE DEPOSITS OF SOUTH * CABOLINA. 215 

washing, and drying the rock is $3.46. The rainy seasons, wliich 
involve extra pumping, and the difficulty of obtaining labor, which 
frequently prevents the plant working to its full capacity, must also 
be taken into account. The present price, which is controlled largely 
by the higher-grade Floiida product, is about $4 a ton. This leaves 
a very small margin of profit and in consequence muiing operations 
have fallen off greatly. 

Grade of 'product .—The South Carolina rock is distinctly lower in 
phosphate content than the Florida product. (See p. 196.) The price 
of phosphate rock is fixed chiefly by the percentage of lime phosphate 
it contains, and the foreign trade generally specifies also a maximum 
percentage of iron and alumina. Before the exploitation of the 
high-grade Florida deposits the South Carolina river rock was very 
popular with the foreign trade, being fairly clean and low in iron 
and alumina. The appearance of the Florida rock on the market, 
however, injured and finally destroyed its export sale and for many 
years the South Carolina product has been sold only in the domestic 
market. 

Although in this country the rock is priced largely according to its 
content of phosphate, certain factors seem to have aided the South 
Carolina product in competition with the higher-grade Florida rock. 
The fertilizer manufacturers find that after calcining it grinds readily 
and cheaply into an impalpable powder, which allows the sulphuric 
acid to act uniformly on the whole mass. The superphosphate formed 
is light and dries readily, and remains in good mechanical condition 
for mixing. Many planters, moreover, prefer fertilizer made from the 
South Carolina rock to that made from the Florida or Tennessee rock. 
There appears to be no chemical basis for this preference and it is 
probably due chiefly to the excellent physical condition of the South 
Carolina fertihzer. 

HISTORY OF FIELD. 

DISCOVERY. 

It is interesting to note that the existence of the phosphate stratum 
was known long before its true nature and value were recognized. 
As far back as 1795^ interest was attracted to the strata associated 
with the phosphate bed by the discovery in them of large numbers 
of teeth and bones. In 1837 F. S. Holmes collected a number of 
phosphate nodules from an old rice field on the west shore of Ashley 
Kiver, but his interest was occasioned only by the fossil shells pre¬ 
served in them. In 1842 Edmund Ruffin made a partial geologic 
survey of the State with special reference to marl and hmestone for 
use as fertilizer; and in his description of the marl on Ashley River 


1 Millar, C. C. H., op. cit., p. 125. 





216 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

he mentions lumps of stony hardness full of impressions of shells.” ^ 
It is remarkable that he actually determined the percentage of lime 
carbonate in these rocks, but finding it to be only 6 per cent did not 
complete the analysis. In 1884 Holmes published a brief description 
of the fossiliferous rocks which he had found seven years before, 
describing them as a “remarkable bed of nodules or conglomerates 
12 inches thick, embedded in clay”;^ and in 1860 again referred to 
them as a bed of silicified fragments of the underlying marl.^ In 
1848 Tuomey^ described the nodules as “marl stones,” from which 
the hme carbonate had been largely removed, leaving chiefly silica 
and alumina. Tuomey evidently relied on Kufhn’s determination of 
these nodules, for although he presents numerous analyses of the 
underlying Eocene marl and points out especially the presence of 
phosphate in it, he gives no analysis showing the phosphate in the 
nodules. 

In a lecture delivered in 1859 before the Medical Association of 
South Carohna, C. U. Shepard referred vaguely to the presence of 
“phosphatic stone” near Charleston. Although he did not specify 
the rock in question, it appears from information quoted by ChazaP 
that he was acquainted with the true nature of the phosphate stratum 
and endeavored to organize a company to mine and utilize it as fer- 
tihzer. The Civil War put an end to these plans, however, and noth¬ 
ing definite was done until 1867, when St. Juhan Kavenel made an 
apparently independent discovery of the nature of the rock. N. A. 
Pratt at about the same time recognized its value, and in company 
with F. S. Holmes immediately made an effort to organize a company. 
As a result of their efforts the Charleston Mining & Manufacturing 
Co. was formed in 1867 and a large area of excellent phosphate land 
on both sides of Ashley Kiver near Tenmile Hill was secured. In the 
meantime Pavenel organized the first manufacturing concern, which 
was known as the Wando Fertilizer Co. 

DEVELOPMENT.^ 

The first small cargoes of hard rock were shipped in April, 1868, 
but it was several years before adequate mining methods were devel¬ 
oped and the work was properly organized. The first washer was 
built at Lambs in 1868, but until 1879 all of the product was shipped 
undried. Moreover, much of the early product was imperfectly 
washed and the land rock acquired a bad reputation, especially in 
the European market, which demanded a low percentage of iron and 

1 Raffin, Edmund, Agricultural survey of South Carolina, p. 35, Columbia, 1843. 

2 Holmes, F. S., South Carolina Agriculturist, 1844. 

' 3 Holmes, F. S., Post-Pleiocene fossils of South Carolina, p. ii. Charleston, 1860. 

< Tuomey, Michael, Report on the geology of South Carolina, Columbia, 1848. 

5 Chazal, P. E., op. cit., p. 40. 

8 This account is taken in large part from the works of Chazal and Millar. 





PHOSPHATE DEPOSITS OF SOUTH CAEOLINA. 


217 


alumina. It was therefore practically excluded from the early for¬ 
eign trade and has always found its best market in this country. 
The hot-air system of drying was begun in 1879 but was abandoned 
in 1882 for the present method of burning over cord wood. Up to 
1888 mining was done almost entirely by hand, and steam shovels 
did not come into general use until about 1895. The Charleston 
Mining & Manufacturing Co., the pioneer concern, had a large work¬ 
ing capital and acquired some of the best phosphate lands in the field. 
In 1868 this company built the first washing plant at Lambs and 
estabfished headquarters there. It has always been the largest and 
one of the'most prosperous companies, although it has had many com¬ 
petitors. Five companies were in the field in 1870, 16 companies in 
1884, and 22 companies in 1891. Many of these, however, were 
small private enterprises and most of them have either ceased opera¬ 
tions or have been absorbed by the Charleston Mining Co. In 1892 
there was a change of management in this company, which resulted 
in the abandonment of the old plant at Lambs and the erection of a 
more costly one at Bees Ferry, a few miles farther down the Ashley. 
This apparently did not lead to the expected decrease in cost of pro¬ 
duction, however, and when the concern sold out to the Virginia- 
Carolina Chemical Co. in 1901 the new owners abandoned the Bees 
Ferry plant and returned to Lambs. In 1904 they completed a new 
plant which had a capacity of 1,200 tons a day and which was then 
the largest in the world. 

The river mining industry, dealing as it did with deposits in navi¬ 
gable streams under the jurisdiction of the State, early became in¬ 
volved in litigation, which hampered it for many years. Owing to 
the fact that expensive machinery was needed for the dredging, the 
operations were carried on by a few large companies, whereas the 
land mining was done by a number of small operators. In 1870 the 
general assembly of the State passed an act giving the Marine & 
Eiver Phosphate Mining & Manufacturing Co. the right to mine 
phosphate rock from the navigable streams of the State for a term 
of 21 years, under a royalty of $1 a ton. This company, which 
began operations in 1870, immediately claimed exclusive rights and 
transferred exclusive rights to mine in Coosaw Fiver to a new con¬ 
cern, the Coosaw Mining Co. The courts, however, later decided 
that no exclusive grant had been made and several other companies 
were formed. In 1876 another act was passed by which the Coosaw 
]\Iining Co. and all other concerns were granted exclusive rights 
within the territory in which their operations had been carried on 
l)rior to the passage of the act. By the close of 1878 ten river com¬ 
panies had been organized and six more were in process of organiza¬ 
tion. The Marine & Eiver Phosphate Mining & Manufacturing Co. 


218 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

ceased operations in 1882, but the Coosaw Mining Co., which had 
exclusive rights to the largest and highest-grade river deposits in the 
whole field, was extremely successful. By 1894 it had produced 
nearly half of the total amount of river rock mined and had paid 
the State about $1,500,000 in royalties. The original lease expired 
in 1891, however, and despite the claim that perpetual rights had 
been granted by the act of 1876, the State, after prolonged litigation, 
finally threw its territory open. During this litigation the company 
was forced to suspend operations and was unable to fill or renew its 
foreign contracts. Up to this time the rock from Coosaw Biver had 
enjoyed a high reputation in Europe, but when the supply was 
stopped the foreign consumers were forced to use Florida rock, which 
thus gained its first foothold and whose superiority became so apparent 
that the South Carolina rock was no longer preferred. The Coosaw 
Mining Co. resumed operations in 1892, but in 1893 a disastrous 
cyclone destroyed the plants of practically all the river companies 
and paralyzed the industry for some time. The richer deposits had 
by this time been exhausted, and the competition of the Florida, 
Tennessee, and Algiers phosphate had become keen; the cyclone 
therefore came at a particularly critical time and injured the river 
mining beyond hope of recovery. The industry rapidly declined 
during the next 10 years, and by 1904 all the large river companies 
had failed or ceased operations. Since 1904 a small amount of 
river rock has been intermittently mined, but the industry as a 
whole is practically dead. 

In the following table is given the amount of South Carolina phos¬ 
phate rock marketed in each year from 1867 to 1913.^ The actual 
amount mined differs slightly from the amount marketed and is 
generally higher. The prices during this period have rauged from 
$10 to less than $3.50 a ton, depending partly on cost of production 
and partly on the market, which fluctuated considerably according 
to the condition of the crops. The prices paid for the river rock 
were generally about $1 lower than those paid for the land rock. 
In connection with the following table it may be noted that the 
Florida rock first appeared on the market about 1889 and that its 
production exceeded that of the South Carolina rock in 1894; and 
that the Tennessee rock first appeared about 1893, increased greatly 
in 1897, and exceeded the South Carolina rock in 1899. Until about 
1885 South Carolina furnished over 95 per cent of the phosphate 
marketed in the United States; at present it furnishes 4 per cent 
or less. 


1 For statistics of production, prices, market, labor conditions, etc., in each year see U. S. Geol. Survey 
Mineral Resources, 1882-1913. 



PHOSPHATE DEPOSITS OF SOUTH CAROLINA. 219 


Production of marketed phosphate rock in South Carolina, 1867-1912, in long tons a 


Year. 


Ending May 31. 

1867 . 

1868 . 

1869 . 

1870 . 

1871 . 

1872 . 

1873 . 

1874 . 

1875 . 

1876 . 

1877 . 

1878 . 

1879 . 

1880 . 

1881. 

1882. 

1883 . 

1884 . 

1885,. 

Ending Dec. 31. 

1885 . 

1886 . 

1887 .. 

1888 . 

1889. 


Land 

rock. 

River 

rock. 

Total. 

Year. 

6 


6 

Ending Dec. 31— 
Continued. 

12,262 


12,262 
31,958 
65,241 
74,188 
58,760 

1890. 

3i;958 


1891. 

63,252 

1,989 

17,655 

1892. 

56,533 

1893. 

36,258 

22,502 

1894. 

33,426 

45 ;777 

79,203 

1895. 

51,624 

57,716 

109,340 

1896. 

54,821 

67 ;969 

122,790 
132,478 
163,000 

1897. 

50,566 

81,912 

1898. 

36,431 

112,622 

126,569 

1899. 

97,700 
98,586 
65,162 

210,322 
199,365 

1900. 

100,779 

1901. 

125,601 

190,763 
206,734 
332,077 
378,380 
431,779 
395,403 

1902. 

142,193 

124,541 
140,772 

1903. 

191,305 

1904. 

219,202 

159,178 

1905. 

250,297 

181,482 

169,490 

1906. 

225,913 

1907. 

1908. 




1909. 




1910. 

149,400 
253,484 
261,658 
290,689 
329,543 

128,389 
177,065 
218,900 
157,878 
212,102 

277,789 
430,549 
480,558 
448,567 
541,645 j 

1911. 

1912. 



Land 

rock. 


353,757 
344,978 
243,653 
308,435 
307,305 
270,560 
267,072 
267,380 
298,610 
223,949 
266,186 
225,189 
245,243 
233, 540 
258,806 
234,676 
190,180 
228,354 
192,263 
201,254 
179,659 
169,156 
131,490 


8,721,518 


River 

rock. 


110,241 
130,528 
150,575 
194,129 
142,803 
161,415 
135,351 
90,900 
101,274 
132,701 
62,987 
95,992 
68,122 
25,000 
12,000 
35,549 
33,495 
28,867 
33,232 
6,700 
0 
0 
0 


4,105,195 


Total. 


463,998 
475,506 
394,228 
502,564 
4.50,108 
431,975 
402,423 
358,280 
399,884 
356,650 
329,173 
321,181 
313,365 
258,540 
270,806 
270,225 
223,675 
257,221 
225,495 
207,954 
179,659 
169,156 
131,490 


12,826,713 


o U. S. Geol. Survey Mineral Resources, 1892, p. 782, 1893. 


PRESENT CONDITION. 

As shown in the table, the production of the South Carolina field 
has fallen off greatly within the last few years and is now about 
equal to the production between 1875 and 1880. No river rock has 
been mined since 1910 and very little in the five years previous to that 
time. Land mining is confined chiefly to the Ashley district, but at 
the time of the writer’s visit only one dredge was operating on the 
north side of the river and two on the south side. The Virginia- 
Carolina Chemical Co. is the principal producer, and only one other 
company is operating. The large washing plant at Lambs is the 
only one now in operation, although in the fall of 1913 three other 
plants were working, two on Stono River and one on Chisholms 
Island, near Beaufort. Under present conditions the price of rock is 
controlled largely by the Florida product, and the margin of profit 
in the South Carolina field is so small that mining is practicable only 
with the use of machinery capable of handling large quantities of 
material. 

FUTURE OF THE FIELD. 

The prospects of a marked revival of mining operations in this 
field are poor. The field attained its importance at a time when no 
other commercial deposits in this country were known and when, on 
the other hand, the widespread need of fertilizer was first being felt. 








































































220 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1913, PART I. 

The increased cost of production, the exhaustion of the richer and 
more accessible deposits, and finally the extensive exploitation of the 
cheap and high-grade Tennessee and Florida deposits have proved a 
combination which the operators have not been able to withstand. 
The foreign trade has been completely lost, and under present condi¬ 
tions the rock can not be shipped out of the State. 

It must be remembered, however, that there are probably at least 
5,000,000 tons of 60 per cent phosphate still in the ground and that 
improved machinery may at some later time render these deposits 
workable. Furthermore, the South Carolina phosphate enjoys two 
advantages. First, the former importance of the field led to the 
building of a group of large fertilizer factories at Charleston, and the 
expense of shipping is therefore almost negligible; second, the rock 
makes an excellent superphosphate, and many planters prefer it to the 
higher-grade rock of the neighboring fields. 

On the other hand, the highest grade rock that the field can be ex¬ 
pected to produce does not average more than 61 per cent phosphate 
and generally exceeds 3 per cent iron and alumina. The cost of pro¬ 
duction is considerably higher than that in the Florida and Tennessee 
fields, so that the 70 per cent phosphate rock from those States can be 
delivered at Charleston at a price only slightly above that of the 
local product. This offsets the saving due to local manufacture, and 
the excellence of the superphosphate can scarcely compensate per¬ 
manently for a difference of 10 per cent in phosphate content. The 
preference for the South Carolina rock is chiefly local, and although 
the demand within the State may continue for some time it probably 
can not affect the general phosphate industry. 

It is probable, therefore, that only a small amount of mining will 
be done for some time. However, as the Florida and Tennessee 
deposits become exhausted prices may advance sufficiently to permit 
the profitable mining of the remaining South Carolina rock. On the 
other hand, the presence of great deposits of high-grade rock in 
Wyoming and Idaho points to an undiminished supply for many 
years and insures crushing competition in the interior part of the 
United States. All considerations, therefore, seem to indicate that 
the South Carolina field has passed its period of maximum produc¬ 
tion, and that despite the quantity and the favored location of the 
remaining deposits the field wiU not for a very long time be an 
important factor in the phosphate industry. 


o 



• -W- 







^ • 




i 




\ 


T 



\ 



j 




.4 





« 







•>r 


JL 


f" 
\ • 



V . • 


is 


fi 

.. '- 
i j :: 




■V.',Vi^i' tv ' 


■- , '■* 

' kV »< 




s. > 






